Improvement in sheet-metal gages



f ,af f y 9 Patented Feb. 8, 1876.

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JQATKINS, l y'SHEET-M'Emu. GAGE.

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NAFEI'ERS. PHOTO-LIYHOGRAPHER. WASHINGTON4 D C.

NITEDL STATE-s JAMEs ArKrNs, or BRooKLYmNEw Yoak.

PATENT -OFFIoa IMPRovEMl-:NT IN-sHEET-METAL GAGEs.

Specification forming part of Letters Patent No. 173,104*e dated February 8,1876; application filed June 2, 1875. e

Toall whom-it may concern Be it lknown that I, JAMES ATKINs,ofv

Brooklyn, Kings county, New York, have invented a Measuring-Gage, of which the following is a specification :v

This invention consists in the construction and arrangement of a measuring-gage for existing on such edges, and whereby all measurements can be made with great accuracy, and the results correctly an d` easily read.

The following .is a detailed description of my invention, reference being had to the accompanying drawing, which represents one of these gages, measuring from zero to threetenths of an inch by the pin C, and four inches by the caliper.

Figures 1 and 2 are views of the two opposite sides ofthe instrument. Fig. 3 is a top view. Figs. 4 and 5 are transverse sections through Fig. 1, on the lines y y anda"v w, re spectively.. Fig. 6 is a perspective view of the end of the larger arm of the frame A, together with the slide B and pin C, with a portion of A removed to more clearly show the relation of these several parts to eaclrl other.

For the same purpose the drawing represents the slide B and the caliper-square partially drawn out.

Similar letters of reference indicate corresponding parts.

A is the frame or body of the gage, divided,

throughout the greater part of its length, into 4two arms, which span the substance to be measured, and made preferably of steel, and of such proportions as to insure the necessary rigidity of the parts. Across one of these arms, near its end, in a suitable slot, moves the pin C, and opposed to. its foot is the projection U on the other arm of the frame. Between `this pin C and projection G' the measurementsA are made, and their opposing faces are made true planes and parallel to each other. The

A pin C'is moved to and from C by the action ofthe inclined planes formed by the faces of the slot D, through the medium of the-tongue e, which is part of the pin C, and lits yaccurately in the slot. The plate B movesin a direction parallely to the length of the larger arm of thel frame A, and, consequently,vat a right angle to 'thedirection of the pin C, this direction being secured by the guides .Gr Gr'.V The angle ofthe slot D with the parallel edges ot'v B, or, in other words, the inclination of the planes, may lvary in different instruments, as their proposed use may require, but should never be large, as on the smallness of the angle, and, consequently, the ,f u'eatfspace through which B moves compared with that through which it moves the pin G, depends the degree of miuuteness to which the measurements can be carried. f

In the accompanying drawing, the inclination ofthe planes is as one in ten, so that a movement of B through vone-hundredth of ani inch shows a movement of one-thousandth of an inch in thev pin C., To indicate the extent of these movements' of G, or the space between the opposing faces'ofO and C', suitable divisions are marked o" on the back-ot' B or other suitable place, and flxed indicating-pointers p p, r their equivalents, are so situated as to point to yzero when 'C and C are in contact with each other, and when the latter are separated' from each other the position of p p on their respective scales indicates the amount of that separation. In the case illustrated by the drawing the divisions of these scales corre spond to movements of C through hundredths of an inch and sixty-fourths of an inch, ref spectively; and on G', to the right'of the pointer p, are marked oft' ten divisions of one- `hundredth of an incli each, by which means measurements can be. read to tllousandths of an inch.

With a properly-proportioned instrument of this kind, the accuracy with which these minute measurements can be made is limited only by the degree of perfection of the tting of the working parts.v

To adapt the gage to measuring by the standard sheet-metal and wire numbers;7 two or more series of divisions are marked off on the back of the frame A, one corresponding to ;cales is easily determined as' follows: Thein-L aline of the slot D being in this case as onein en, the mark in the scale corresponding `to ach number is distant from the Vzero-mark ust ten times the size of that number. Thus No. l iron (Brown & Sharpe standard) is 268595 inch thick; hence the mark on the scale enotingthat number is ,208690 X 10:2{59 inches i'rom the zero-mark. 1240, 30 is vo'nelhundredth inch thick; hence, its corresponding mark is 4one-tenthl inch from the 'zero-markln the scale.

Passing through the plate B and slot S in frame A, and moving with B, is the screwclamp fn, by means ot' Which'B and G Vmay be held in any desired position. A

Movable in the groove I in the smaller arm of the frame `A is the slide and jaw F`F,form

ing, with the end of A, a sliding caliper, which may be graduated to even divisions of the inch, and by means of a Vernier may be read to thousandths of an inch, as sliding calipers are ordinarily marked. F is so constructed, also, 'that it maybe used as a machinists square.

The gage may be made of any size, from a small pocket-instrument to a heavy stationary one for the use of manufactories, Svc.

Having thus described my invention, I claim as new and desire to secure by Letters Pat- -ent- 1.l The combination of the frame A, pin C, slide B, the graduated scales on A and B, and the pointers P and p p, or their equivalents, substantially as and for the purpose described.

2. The combination of the frame A, slide B, and'pinC, and the'caliper-square F, substantially as andI for the purpose set forth.

JAMES ATKINs.

Witnesses: 1

DAvIDS. PARKER, A YA. D. RoNALDsoN. 

